The developed models are appropriate for application in waste management practice with respect to their excellent coefficients
of determination, namely R2 = 0.99, 0.99, 0.98, and 0.98, their low errors of cross-validation and their high
ratios of performance to deviation (RPD = 9.3, 12.5, 6.5, 7.3). Thus, FT-IR spectroscopy turned out to be a
reliable, time-saving tool to determine four parameters relevant for landfill aftercare monitoring by one
single easy adaptable measurement.